News Centre

The Ambatovy laterite-nickel project on Madagascar will consist of the largest nickel pressure acid leach plant in the world. SNC Lavalin awarded the contract to Weir Minerals Netherlands for the supply of ten (10) sophisticated Geho triplex Heatbarrier pumps. This significant contract confirms that the Geho positive displacement pump technology is the standard in today’s mineral processing technology.

History

In the early 1960’ a significant resource of mineable nickel was identified in the island nation of Madagascar, off the east coast of Africa. Phelps Dodge started an intensive drilling programme in 1995 to ascertain the economics of developing the mine. Later it sold its share and the present ownership is split between Dynatec, Sumitomo and SNC Lavalin.

The Malagasy government is very supportive of the project which will provide a strong boost to the country´s economy. The plans envisage the development of the mine site, an adjacent ore preparation plant, a pressure acid leach plant and the refinery and port facilities on the coast. The ore will be transferred to the coast through a 220 kms slurry pipeline.

Geho PD pump technology

The pressure acid leach of laterite ore will take place in 5 parallel process trains each consisting of a feed tank, slurry heaters, two Geho PD pumps, an autoclave and flash vessels. The ore slurry received from the thickeners will be heated with steam in a series of direct heaters and pumped, continuously, at a temperature of up to over 200°C into the autoclaves where it will react with sulphuric acid at 260°C. The products such as nickel, cobalt, copper and zinc will be dissolved and later leached by reaction with oxygen.

The pumps to be supplied are, in principle, identical to the pumps in operation at Rio Tuba´s Coral Bay refinery in the Philippines, although the water end materials now used are made of super duplex. Additional benefits are the immediate implementation of lessons learned in previous ramp up phases.

Due to the abrasive effect of the slurry at these pressures a rubber diaphragm is used to protect the pump´s vital parts from contact with the slurry. One major challenge in these types of pumps is to keep the high temperature slurry away from the diaphragm for which Weir Minerals Netherlands developed the Geho PD Heatbarrier design. The only other wear parts in contact with the slurry are the valves. Weir Minerals Netherlands will supply their special design Outlast® valve to achieve exceptional abrasion and corrosion resistance.

The selection by the customer of Geho piston diaphragm pumps for this project follows the Australian Minara, Bulong, Ravensthorpe and the Philippine Rio Tuba projects, which demonstrate that the special Geho PD pump designs and after market support by Weir Minerals Netherlands for this particular application are much appreciated by the industry.